Catharsis
by Last of the Loneliness
Summary: There is no sweeter innocence than our gentle sin.


**A/N: What can I say? It was inevitable. Reviews appreciated!**

**Trigger warning for nonconsensual sibling sexual abuse and incest. **

* * *

Something is wrong with his sister.

She is very close to him and breathing in the dark. He is afraid to move, afraid to speak. She has entered without warning and he doesn't know what she wants with him. He does not want to provoke her. The knowledge that their mother is no longer there to break up their squabbles bears heavily on him. Six months gone and still he misses her as if she's only just left. His mother has left him defenseless. Though he would never admit it, he fears his sister, the prodigal talent that lies in her fingers.

It is too dark for him to see her very clearly. Her eyes are the lightest part of her, fixed insistently on his face, not moving or blinking. He stares up at her. She is between him and the door, and he doesn't know where he would run anyway.

"Azula?"

It comes out too loud, of course, disturbs the silence. Her eyes refocus, but it is too dark for him to see the small changes in the muscles of her face. But he does notice when her hand slams down on the other side of his head. She is pinning him there, though she isn't touching him, though he's stronger than her and could probably throw her off if he tried.

He doesn't try. He doesn't know what to do or think. He was asleep before she came in, and half of his mind is still sleepy, slow to function and comprehend. His sister has never acted like this before. He wonders whether she's sleepwalking, or sick, or—

She's getting closer. He can feel and smell her breath against his face. There is something sharp and unfamiliar in its scent. Her hair falls low and touches his skin. It's not tied up like usual, but flowing down around her face.

"What are you doing?" He can't entirely keep the panic out of his voice. His sister, though she's looking at him, doesn't really seem to be seeing him at all. She's looking past him, into him, at something he can't see.

"It's okay," she murmurs, very quietly, into his ear. "It's okay. It's okay. It's okay. It's okay."

This is the last response he expected, and it terrifies him. His sister doesn't even seem to be mocking him, which would be usual. She sounds, rather, as if she was soothing a frightened animal. He doesn't know what to make of any of this.

"I want to show you something," she says, then, a little bit louder. Her words fall over each other in a way he's not used to. Usually she seems confident of everything she says.

"Can't it wait 'til morning?" He's truly afraid now. What if she's come to kill him? In the night, in the darkness, with her strange words and stranger actions, it doesn't seem entirely impossible. He wants witnesses, wants daylight, even wants their father as a shield there.

"No," she whispers. He hears the sound of her legs sliding against the sheets and then realizes she's straddling him. His heart beats faster and faster, and his breath follows suit.

"I don't want to do this! Azula, go back to bed! This isn't-!"

"Shhh," she says, so calming, so quiet, and the next second she's stuffing the sheet into his mouth and holding it there. He tries to spit it out, but there is no helping it, and it takes a few horrified seconds to remember he can breathe through his nose. Only then does he start wriggling, trying to throw her off, trying to free himself. Is she trying to smother him? Is this how he dies, murdered by his nine-year-old sister in the middle of the night?

Then he feels a searing hot hand clamping on his shoulder and growing hotter. He yells through the sheet, the sound muffled, and Azula lets go.

"I'll take it out if you promise to be quiet," she says.

Zuko nods as best he can.

"If you make too much noise, I'll burn you for real this time." Her breath tickles his face. Its scent is abhorrent. Everything about this is revolting. He is trapped in the dark and he doesn't know how to escape, and he's afraid to guess about what happens next.

She pulls the sheet out and throws it aside. Zuko's in the midst of catching his breath when a hand on his waist brings him up cold. Azula is undoing the tie that holds his sleeping robe shut. He feels the cloth part, feels cool air on his skin, and then—

"Stop it!" He forgets the threat of pain and squirms again. Horror and fear are warring inside of him. He doesn't want his sister to see him naked, doesn't want her to touch him there. He doesn't understand why any of this is happening; what's wrong with her?

"Shh, or I'll gag you again," she says. Still her tone is soft and soothing, but that serves only to terrify him more. "It'll feel good, I promise, okay?"

He stops wiggling, because her hand is still on his shoulder, and he doesn't want to hurt. He would close his eyes, but the only thing scarier than seeing her would be not seeing her. "I—I'm going to call for help. You should leave."

"It's the middle of the night, Zuzu," she sighs, and this is close enough to her usual self that it's almost comforting. "Nobody will hear you. You can scream all you want, but then I'll shove the sheet in your mouth again. Your choice."

Tears are forming in his eyes, and he refuses to let them fall. He doesn't want to show her what she's doing to him, exactly how afraid he is. But he goes still and silent, just as she wants, and after a few seconds she smiles.

"Much better."

It takes a concerted effort not to speak or move as Zuko feels her hand wrap around his penis and begin stroking. He focuses on his breathing, on in and out, and tries not to think about the things his little sister is doing to him.

"It's okay," she murmurs, and he hears the sound of cloth against skin again. She's shifting over him, and the next thing he knows, something warm is pressing against him. Then she slides down.

He tries not to think about it, but he can't stop himself, for his sister's promise of pleasure is too accurate. He doesn't want to feel the things he's feeling, doesn't want to think about what Azula is doing to him, what he's doing to her. This is wrong, isn't it? He's afraid to think too much, in case he cries, because she would surely mock him for the tears.

Amidst his trying not to think, trying not to feel, he hears a low noise and realizes that his sister is whispering something over and over again. He listens without really meaning to, and then he wishes he hadn't.

"It's okay, it's okay, it's okay, it's okay, it's okay, it's okay, it's okay, it's okay..." she says, a hypnotic chant, and he wonders whether she's speaking to him or herself. The only thing the mantra achieves is to reinforce to him that everything is most certainly not okay.

Zuko has played with himself before, felt the heady sensations that consume him when he runs his fingers over his penis, but it feels different now. It's not his hand that's touching him, but something wet and warm and different. Everything about this is too different, too foreign, too wrong. He doesn't know why Azula's doing this. He just wants it to be over, wants to fall asleep and pretend in the morning that nothing happened.

His wish comes true. He feels pleasure rushing over him. A sound, half-gasp, half-groan, slips from between his lips, and he instantly hates himself for it. Azula pulls off of him and leans down. She's burning hot. He just feels cold and empty, chills of pleasure still making their way across his skin. There's no point in resisting anymore, not when it's over.

"I told you it would feel good," she says, and then she kisses him. Then she gets up, and he hears the door open and close. He turns over and ties his robe closed, trying not to think about the sticky mess on his legs and on the sheets.

When she's gone, he feels safer. In that dark room, in the dead of night, with his mother long gone, Zuko buries his head in his pillow and cries.

In the morning he tries to forget about it, and mostly he succeeds, because she doesn't bring it up either. But in a week she comes back.

* * *

He is twelve. It is early evening, and he finds himself in his sister's rooms. He doesn't know how to say what he wants, because he's still ashamed of it, and he still knows it's not right. He hasn't told his uncle, hasn't told his father, hasn't told anybody, so it's just a secret that lingers between the two of them. And now, when physical desire catches hold of him, he goes to her, because he's become accustomed to her relieving him.

She greets him with a twisted smile and he half-expects her to turn him away, but she doesn't. She removes her armor, layer by layer, as he lies on her bed and watches. It gives him a hint of pleasure to think that nobody else has ever seen her like this, so vulnerable. He sees her at her weakest, and that knowledge helps settle the jealousy inside him.

She looks much older now. He doesn't know whether she's grown that much in a year, or if his perception of her has just changed, but she seems nothing like a child. She paints her lips and stands as if she owns the world. Their father's favor shines on her.

She's finished with her armor and is down to her clothing now. He watches with perverse enjoyment as she pulls layers away; usually it's too dark to see anything. When she lets her hair out of its bun to fall over her shoulders, he feels a throbbing between his legs. His blood seems to burn as the cloth falls from her skin, leaving it smooth and exposed.

She smirks when she notices his gaze and the obvious tent in his pants.

"Enjoy it that much, Zuzu?" She crosses the room with a sinuous grace and slides down onto the sheets beside him. He sees a pattern of bruises across her chest and frowns.

"How'd you get those?"

"Get what?" Her lips on his neck make it hard to think properly.

"Those...bruises."

She pauses for a second to glance down at them herself, and then she laughs. "Proper battle training's rough, Zuko. I suppose you wouldn't know."

Then she positions herself and in an instant he's inside of her, and Zuko's brief curiosity vanishes in a flare of pleasure as his sister clenches tight around him. He thinks, blissfully, that nothing that feels so good could possibly be wrong. As long as he doesn't think about guilt, it's easy to keep it at bay. There is no reason to surface, no reason to think about anything but the sensations she draws from him.

The signs are all there, and he does find himself wondering, on occasion, how she's so good at this. When her hips press against his, and her hands lock in his hair, and she licks and sucks across his shoulders and chest, it doesn't feel as if he's being ravished by a ten-year-old girl.

But he doesn't think about that, because then guilt pools like hot, molten metal inside of his stomach. It's much better to think, instead, about the pleasure running through him, and the breathy gasps escaping her lips, and the way they move together. Blood and blood, flesh and flesh, brother and sister, and if he doesn't acknowledge how wrong it is then it can't be that sinful, can it?

It's over, and he's lying back to bask in the afterglow, but when she turns away from him and bends to retrieve her clothes from the floor, he sees more bruises marring the canvas of her skin across her thighs and buttocks, dark and purple and green, and he frowns, wondering whether she really got marks like that from training.

Like the rest of this, he shoves it out of his mind, because thinking too much will lead him down avenues he doesn't want to travel, and he'll end up in dark corners where he has to face truths that he doesn't really want to know at all.

* * *

The pain of his face is the worst he has ever felt, will ever feel, but in some ways he's glad for it, because no matter how much it hurts, it is a welcome distractor from the horror and numbness filling him. The truth of the matter still hasn't hit him. Everything has happened so fast. Just a handful of days ago he was crown prince, unmarred, woefully unaware of the future that awaited. Now his father has burned him beyond repair, stripped him of his title, and has sentenced him to exile. He doesn't know what to think or feel. All he can do is think of his father's shadow looming over him, and the pain, the heat of fire on his face as his flesh melted and disfigured.

All his sleep since then has been disturbed and uneven. He wakes in the night, still screaming. All of his dreams are red and orange and hot, and he hasn't bent since the mockery of an Agni Kai, for even the familiar sight of his fire would be terrifying to him.

"So you're leaving tomorrow?"

She hasn't left his side. He hates her. She hasn't stopped smiling. He can't ignore it, that hideous grin on her painted lips. She wanted it to happen. She's enjoying every last second of this. Every time he lets out a grunt of pain, every time the doctors change his bandages and he has to yell, he sees her lips part and mad fervor glint in her eyes. There is something wrong with her, a fact that he's always known but that becomes all the more apparent now.

The doctor has left him alone for the night, his last night in the palace. He's trying not to think about it, but it's like trying not to think about the burn. It's always there, and his mind is drawn inevitably back to it. His sister is sitting beside the bed, but as she speaks, she stands. He has to turn to see her, and he hates it. He feels so blind without his left eye, and constantly vulnerable. She could attack him from that side, and he would be none the wiser.

She doesn't, though. She kneels down on the sheets beside him and runs her hand across his face. Somehow it manages to be cool despite her usual heat, and he flinches at the touch. She laughs, of course. Her fingers stroke his intact skin and then move across the bandages. There isn't enough pressure for him to feel pain, but he braces for her to dig her fingers in or something similar.

"It's too bad. Now I won't have anybody to play with. And you'll just have your hand, Zuzu, and I'm sure that's no good compared to me."

She laughs again, ecstatically, as if what she said was the best joke she's ever heard. Zuko turns his head away from her, fighting the anger building in him, trying to ignore her. It's not a simple task. Azula has always been extremely skilled at getting the reaction she wants out of her big brother, and this time is no different. When he makes it clear he's not interested in a conversation, one of her hands grabs his head and turns him back to face her.

"One more time, I suppose, for old times' sake," she sighs, as if it's a great effort. Zuko tries to protest, but her fingers press against his bandaged eye and he's silenced as pain stabs through him even just from that contact.

It's in the dark, like their first time, and Zuko only wants it to be over. He doesn't want to look at her or think about her, to listen to her breathy taunts about what his banishment means. She holds his head in place and forces him to look into her eyes as she moves up and down upon him. He hates her for laughing at him.

"How did it feel?" she asks, in the midst of it, leaning down close to whisper in his ear. "How did it feel, when he burned you? You screamed so much."

He wishes she would shut up. He wants to gag her, _burn_ her, even kill her, anything to stop her from taunting him. Sooner or later, it won't always go the way she wants. Sooner or later, he'll come out on top, and she won't be laughing then.

"_Did you want to die_?"

It can't last too long, but to Zuko it feels like an eternity before his sister gets what she came for when he climaxes. And as much as he loathes her, as wrong as this is, he can't deny that the few seconds of pleasure manage to drown out the pain.

"Now you know how it feels," she says, fixing her clothing and wiping faint traces of sweat from her face. She's finally going to leave, and he feels relief at the prospect. "Don't pretend you didn't enjoy it." And before he can ask whether she's talking about the burn or their fornication, she's disappeared out the door. Zuko's head slams back against the pillows and he squeezes his eyes closed, trying to erase her smile from his mind.

He doesn't see his sister again before he leaves.

* * *

Everything is wrong.

Homecoming is bittersweet. He sees his sister's smile and finds it disturbing. When he remembers her words in the crystal chambers underneath Ba Sing Se, he doesn't know what to think. _I need you,_ she said. Now he has to think about how she meant it, a task that has been complicated infinitely by Mai.

He likes her. She is steady and solid, gently teasing, kind in a way completely different from Iroh's kindness. She is right for him, a noble girl with rich parents, and he can't help but admire her skills with all sorts of weapons. Her eyes are mild but see quite a bit, and maybe she notices how he reacts when she kisses him. He can't help it. She's only the third girl he's ever kissed, and the other two were so different. He had the same reaction to Jin, in Ba Sing Se, but there his true heritage was a problem as well. Now, whenever he touches Mai, he feels Azula's eyes on him, whether she's there or not. Whenever he kisses Mai, he can't help but wonder whether he'd rather be kissing his sister.

He swallows the feelings and tells himself he likes Mai, tells himself he loves her. He has so many other things to worry about than that, like how his father will receive him, and why this homecoming feels off. But all of his worries coalesce after he discovers what Azula has told their father. The walk to her bedchambers is too familiar for comfort, and he must repeat over and over again to himself that he is only there to confront her. Their affair is in the past. She has no power over him anymore.

Of course, as soon as he sets eyes on his little sister, those comforting lies evaporate. How long has it been? How much has she grown? Seeing her in battle armor didn't disturb him the way this does. Her hair is out of its usual perfect bun, her face is without makeup, and it is all too reminiscent of the things she used to do to him. Anger and arousal war inside of him, and she knows it, judging from the look on her face. Even with her eyes closed, she manages to look impossibly smug.

"Why did you do it?"

"You're going to have to be a little more specific," she purrs. That makes him angry enough that he almost wants to stride over and hit her, hurt her, make her stop tormenting him. She knows full-well what he's talking about.

"Why did you tell Father that I was the one who killed the Avatar?"

"Can't this wait until morning?"

"It can't," Zuko growls.

"Fine." Azula finally sits up, and Zuko looks at her. She is not just a girl any longer. As if by magnetism, his eyes are drawn to the skin of her neck and chest, where the curves of her breasts are hidden by the robes. His heart begins pounding faster. He hates himself for this reaction, but he can't stop it. He feels as if he's falling down a long dark hole, but he's been down there before.

She studies her nails as she speaks. "You seemed so worried about how Father would treat you because you hadn't captured the Avatar. I figured if I gave you the credit, you'd have nothing to worry about."

"But _why?_" Nothing is simple with her. The answers are never what they seem. No matter what she says, Zuko knows she doesn't care about him.

"Call it a generous gesture." She stands, and Zuko clenches her teeth. Her legs. The swing of her hips. She's doing this on purpose, isn't she? "I wanted to thank you for your help, and I was happy to share the glory."

"You're lying!" Zuko is only half-focused on the conversation anymore. Half of him is solely fixed on staring at his sister as she moves closer. Every step seems to last forever. He can hear his heart beating in his ears. He desperately tries to deny himself what he wants.

"If you say so." To his great relief and great disappointment, she doesn't stop in front of him, but walks past him. His eyes linger on her face, so imperious in profile.

"You have another motive for doing this. I just...haven't figured out what it is." Zuko himself couldn't say whether he's talking about killing the Avatar or something else, something filthy and wrong that lies in the past and underneath both of their voices.

Azula stretches. He watches, of course. He can't help himself. Her back is to him, and it would be so easy to attack, to throw fire, to pin her against the wall...

Then she turns, and he controls the impulse.

"Please, Zuko. What ulterior motive could I have? What could I possibly gain by letting you get all the glory for defeating the Avatar?" She moves closer, and this time she stops in front of him. Zuko's breathing is getting shallower. He doesn't know what he's going to do, or what she's going to do. When she places a hand on his shoulder, their faces mere inches apart, all he can think about is how grateful he is for the bagginess of his pants. "Unless _somehow_ the Avatar was actually alive." The moment ends. She moves on toward her bed. Zuko breathes again. "All that glory would turn to shame and foolishness. But you said yourself that was impossible."

She slides back under the sheets, still smiling at him, the smile that says more than any outsider would know. As if his feet are leaden, Zuko turns to go.

"Sleep well, Zuzu," she says.

He makes his slow way out of the room, too caught up in his thoughts to bother closing the door behind him. In some way he feels as if he was just tested, though he has no idea whether he's passed or failed. All he knows is that, with every step further away from his sister, his thoughts grow darker and darker, and his feet grow heavier and heavier.

* * *

His saliva is hot and thick in his mouth, like blood, like tar. His head is clouded with sinful thoughts. Some part of him is screaming that this is wrong, that he should turn back now, that he can still save himself. He thinks of Mai, and how good she has been to him, and how being with her feels more like being home than the palace does. He thinks of his mother, and what she would say if she could see him now. He thinks of his father, and what he would say if he knew the things his children do in the dark.

(What Zuko doesn't know can't hurt him.)

But he keeps walking, because of the blood connecting him and his sister, because of the things she has done to him, because despite how much he hates her he loves the feelings she arouses in him. He has gorged himself too deeply on her poison, and now he needs it to complete him.

Down

and down

and down

the hole.

At her door is the last chance to turn back, but Zuko doesn't take it. He opens the door and enters, like a fly entering a spider's web, and Azula is there waiting with a smile and a promise of sin on her lips. It is so dark, like when they were children, but Zuko is not a child anymore. He is a man, still making foolish decisions, still letting everybody down. Never has he felt more incomplete than when he stands in the center of his sister's bedroom and allows her to disrobe him. When did this happen? When did he turn into what he is? When did honor dissolve into disgrace and shame? Why is his uncle locked away in a prison cell while he stands nude before his sister?

He doesn't have answers to any of the questions, but when Azula smiles and takes him by the hand and pushes him down on the sheets, he knows.

She is his answer.

(Now he is bigger and stronger and he manages to pin her down for once, and in the dark he doesn't have to think too hard about the bruises on her skin or the way her face changes or how her movements have become stiffer, automatic, rehearsed.)


End file.
